diff --git a/include/ircd/fs/read.h b/include/ircd/fs/read.h
index 0483d51c7..f1d748784 100644
--- a/include/ircd/fs/read.h
+++ b/include/ircd/fs/read.h
@@ -32,6 +32,9 @@ namespace ircd::fs
 
 	// Prefetch data for subsequent read(); offset given in opts (WILLNEED).
 	size_t prefetch(const fd &, const size_t &, const read_opts & = read_opts_default);
+
+	// Evict data which won't be read anymore (DONTNEED).
+	size_t evict(const fd &, const size_t &, const read_opts & = read_opts_default);
 }
 
 /// Options for a read operation
diff --git a/ircd/fs.cc b/ircd/fs.cc
index 0ad5149a5..c2615c328 100644
--- a/ircd/fs.cc
+++ b/ircd/fs.cc
@@ -486,14 +486,31 @@ ircd::fs::read_opts
 const ircd::fs::read_opts_default
 {};
 
+size_t
+ircd::fs::evict(const fd &fd,
+                const size_t &count,
+                const read_opts &opts)
+{
+	#if defined(POSIX_FADV_DONTNEED)
+		return advise(fd, count, opts, POSIX_FADV_DONTNEED);
+	#else
+		return 0UL;
+	#endif
+}
+
 size_t
 ircd::fs::prefetch(const fd &fd,
                    const size_t &count,
                    const read_opts &opts)
 {
-	return advise(fd, count, opts, POSIX_FADV_WILLNEED);
+	#if defined(POSIX_FADV_WILLNEED)
+		return advise(fd, count, opts, POSIX_FADV_WILLNEED);
+	#else
+		return 0UL;
+	#endif
 }
 
+#if defined(HAVE_POSIX_FADVISE)
 size_t
 ircd::fs::advise(const fd &fd,
                  const size_t &count,
@@ -518,6 +535,16 @@ ircd::fs::advise(const fd &fd,
 	while(off + cnt < opts.offset + count);
 	return count;
 }
+#else
+size_t
+ircd::fs::advise(const fd &fd,
+                 const size_t &count,
+                 const read_opts &opts,
+                 const int &advice)
+{
+	return 0UL;
+}
+#endif
 
 bool
 ircd::fs::fincore(const fd &fd,